This invention relates to firearm safety devices, and more particularly, to mechanisms for preventing accidental firing of a partially electronically controlled firearm.
As society has moved further and further from rural, agricultural and hunting population bases towards urban population centers, there has become a greater and greater concern for firearm safety. Of particular concern are incidents of improper handling of firearms by unsanctioned individuals that lead to disastrous results.
Also, firearms have traditionally been advantageous, when properly understood and used, for protection against would be perpetrators of crimes against the property, homes, family and person of law-abiding citizens (xe2x80x9cMore Guns, Less Crimexe2x80x9dxe2x80x94Professor John R. Lott, Jr. 1996, University of Chicago). Yet there is a concern that firearms may be accessed by unauthorized individuals or children. Further, there have been instances in which citizens and police have had their firearms taken from them by intruders, suspects and criminals who then use the firearm against the rightful owner. Thus, there is a need to reduce such incidences of accidental or intentional access by unauthorized persons and children and there is a need to reduce instances of firearms taken from individuals and police officers to be used to assault the individuals or police officers.
As one of the safeguards of our freedom, the Constitution of the United States grants every lawful citizen the right to bear arms. At the same time, however, general access to firearms necessitates societal responsibility to ensure that incidents of gun injury are minimized. Thus, there are two simultaneous needs: the need for free people to own firearms if desired and a need to promote safety through education and by offering the choice of additional safety enhancement features to those who may benefit from them.
Many safety devices for firearms have been proposed in the past. However, a device that adequately addresses the personalization of a firearm has not been devised prior to the present invention. For example, safety devices using mechanical keys have been devised; however, keys require keeping track of the key and locating the key before using the firearm. In times of fear or panic, the act of inserting the key prior to operation can lead to difficulties and inability to use the firearm for protection in an emergency. The firearm, once activated with the key, can be taken from the rightful owner and continued to be used as long as the key remains inserted. This does not address many of the concerns regarding firearms to be used for protection or that might be taken away from the rightful user.
Another previously proposed safety mechanism requires mechanical manipulation to cause certain slides and levers to be moved into proper position for allowing firing. Although the requirement that the owner must learn and use certain complex movements, providing a modicum of additional safety, it nevertheless also interferes with prompt use for defense purposes. Also, once the movements become generally known, anyone having this knowledge may use the firearm. Moreover, the risk of accidental xe2x80x9csuccessfulxe2x80x9d manipulation of the device by a child continues to exist.
Magnetically activated switches or magnetically moveable slide mechanisms for blocking the firing mechanism have also been proposed. However, devices that do not discriminate as to the strength of the magnet required can be activated by anyone having a magnet.
Magnetically activated switches having a particularly selected magnetic strength range have also been proposed. Such devices successfully permit only an individual having the proper strength magnet on a finger ring to operate the firearm. It has been found that such devices are useful for a limited number of selected field strength ranges and thus to distinguish between those without magnets and an individual user having a magnetic ring with the appropriate strength. These devices act quickly in emergency defensive use situations, but nevertheless face some drawbacks with respect to the limited number of selectively distinguishable strength ranges for magnets.
Handprint and fingerprint identification devices have been proposed in which the grip of the firearm has sensors that are connected to a microprocessor to detect distinctive prints of an authorized user. However, the power requirements are significant and tend to prevent practical usage. Also, the complexity, the reliability and the sophistication of the computerized identification of handprints and fingerprints have made this proposed solution very expensive and impractical for wide-scale adoption. Fingerprint identifications are likely to fail when the grip is wet with rain, condensation or another liquid or when hands are wet, sweaty, dirty, greasy or otherwise soiled or when gloves are worn. Any or all of these factors could be present when use of the firearm is appropriate by a peace officer, the rightful owner or another properly authorized individual.
Personal identification of an authorized user through radio transmission of a coded signal from a user to a transceiver has also been proposed. Such a device, however, requires both an adequate power supply mounted in the firearm for operating the transceiver and the safety mechanism and also an adequate power carried by the user supply for operating the transponder or transmitter carried by the authorized user. Moreover, radio transmission and reception generally requires an antenna having a length equal to one-fourth of a wavelength. Thus, for frequencies lower than the gigahertz range the transponder can be quite large. To date, this proposed solution has been impractical and has not been successfully implemented for commercial applications. Some of the problems include the onboard power supply being continuously drained while awaiting receipt of authorized radio signal transmission. Also the transmitter/transponder carried by the authorized user must have an adequate power supply. The risk is significant that the battery power of a stored firearm will become depleted and will thereby prevent use of the firearm by the authorized user at inopportune times. No one wants to be looking for and replacing batteries when an intruder invades their home. Further, the personalized transmitter/transponder can be larger than an ordinary ring in order to accommodate an adequate antenna size or to provide adequate power for continuous availability of the firearm for use. Radio transmission also typically provides for reception distances of more than a few feet, which is generally sufficient for close range use of a firearm against the authorized user. This is not acceptable for situations where a police officer might have a firearm wrested away in a scuffle with a suspect. Also traditional radio frequency signals are subject to many types of outside interference. For example high voltage noise, other radio broadcast, large transformers, certain electronic equipment and even lighting. Even sun spots have been suspected to have caused radio controlled garage doors or other radio controlled equipment to open.
Another device shown in U.S. Pat. No. 5,564,211 provides for a directional radio signal wherein the authorized user has a transmitter and the firearm has a receiver. The receiver is designed to deactivate the firearm whenever the directional radio signal indicates that the firearm is pointed at the individual having the authorized radio transmitter. Such a device is clearly useful for certain purposed as it is designed to reduce the risk of a firearm being used against a rightfully authorized user. Once again, these devices have significant power requirements, both for the receiver and the transmitter, so that they suffer from some of the drawbacks as with some of the other prior radio coded devices.
Voice identification and voice activation firearm safety devices have also been proposed. Problems arise with properly programming voice identification or other voice command activation signals so that such signals cannot be duplicated by others. The complexity of computerization using microchips and/or software that is required for voice identification continues to challenge currently available technology and is still very costly. The solution is not yet practical. The power requirements are still problematic. Also, the need in certain situations, particularly hunting and police work, to quietly activate a firearm without talking or without another audible signal, further tends to make this proposal less than adequate.
An electromagnetic solenoid blocking mechanism has become popular among proposed safety devices since it was first suggested in U.S. Pat. Nos. 5,016,376 and 5,123,193. Safety devices for use with electronic firing firearms have been proposed as an alternative to mechanical or electromechanical blocking of firing mechanisms of firearms. Such alternative devices might avoid some requirements for mechanically or physically blocking the trigger or firing mechanism that has been suggested for most proposed firearm safety devices. The proposed alternative electronic firing devices are complex and the technology for electronic firing is not yet available as a commercially feasible product. Moreover, electronic firing also continues to require a personal identification system that is sufficiently selective, and sufficiently reliable with adequate power and that previously has not been adequately addressed.
Thus, a need has been identified for a firearm safety system that is reliably enabled only by an authorized individual. The need is one for a device providing close proximity activation by a conveniently small personal identification device, preferably an adornment, held, carried or worn unobtrusively at a location on the individual that is brought in close proximity to a firearm when it is used, such as an unobtrusive piece of jewelry or a finger ring. It is desirable that the identification adornment be one that can be worn continuously for purposes of police work and for sport shooting, hunting and personal protection. One should be able to sleep with the adornment on so that nighttime home protection is a practical option. The safety enhancement mechanism should operate automatically and reliably without interfering with other existing manually operated safety mechanisms already present on most firearms. The system should provide for a large number of different personal identification codes. The device should be factory programmable and preferably factory re-programmable so that, in the event that the identification device is lost or stolen, the firearm can be reprogrammed for use with a replacement identification device or adornment and so that the firearm cannot be operated by another having possession of the previously lost or stolen identification adornment. Advantageously the device should not be programable by individuals. Unsanctioned users and children should not be able to reprogram the system to make themselves authorized users. The needed safety enhancement device should also provide a reliable power source portably carried with or in the firearm so that the identification device or adornment does not require its own separate power supply and can therefore be made small and convenient to carry and preferably continuously wearable.
The portable power supply should reliably warn the user when the power is low; but should continue to operate reliably until the warning is heeded and the power supply is replenished.
The mechanism used to prevent and selectively enable firing should be resistant to inertia due to rapid movements of the firearm to increase reliability of the enhanced safety system.
The foregoing and other objects and advantages have been accomplished and provided in the firearm safety enhancement system and device of the present invention. The invention provides a xe2x80x9cpreventerxe2x80x9d for preventing firing of a firearm without power being applied. It is provided with a reliable portable battery power supply. A proximity or system xe2x80x9conxe2x80x9d switch connects the power supply to an interrogation circuit when a personal identification device is in close proximity to the interrogation circuit or simply when a user handles the firearm. The interrogation circuit electromagnetically checks the immediately surrounding environment for an authorized personal identification code stored in the personal identification device. The personal identification device is secured in a small personal adornment carried or worn by the authorized user, preferably, the adornment may be a finger ring, or other small unobtrusive piece of jewelry, that is automatically brought into close proximity to the firearm when it is to be used. Preferably, the personal identification device comprises a passive tag that is programmed with an individual identification code. The passive tag advantageously receives power transmitted from the firearm in the form of an electromagnetic wave or power signal. The passive tag receives and is activated by the power signal from the firearm in the form of electromagnetic energy. Upon activation, the passive tag provides a coded return signal corresponding to the personal identification code. The coded signal is read by a reader circuit in the firearm. When the code provided by the identification tag matches a preprogrammed code stored in the reader circuit, the reader circuit acts to retract the preventer mechanism so that operation of the trigger and firing of the firearm is enabled. With the firearm thus enabled, the authorized user can then choose to pull the trigger and discharge the firearm.
Thus, what has been provided is a firearm safety enhancement system comprising at least one preventer, preferably a preventing solenoid, operatively connected in the firearm. The preventer has a blocking position to prevent firing and a firing position to allow firing. An electrical activation circuit is operatively connected to the preventer to move the preventer between the blocking position and the firing position. A portable power supply is held in the firearm and is coupled to the electrical activation circuit for providing electrical power. A power signal transmitter is mounted in the firearm, coupled to the portable power supply for transmitting an electromagnetic power signal. A passive identification tag is mounted in a small adornment, such as a small piece of jewelry, and preferably a finger ring. The passive identification tag is responsive to the electromagnetic power signal transmitted from the firearm and becomes energized upon receiving power therefrom. Upon receiving power from the power signal, the passive tag activates a return signal carrying a personalized identification code preprogrammed into the microcircuitry of the passive tag. A reader circuit is provided in the firearm that is responsive to the personal identification signal to activate the electrical activation circuit only upon detecting a personal identification code that matches an authorized code stored in the reader memory. When the matching code is detected, power from the portable power supply is connected by the activation circuit to the preventer causing it to move from the prevented position to the unblocked position. When the firing mechanism is unblocked, and assuming any other mechanical safety is also off, the firearm can be fired by the authorized user.
According to another aspect of the invention, the power signal transmitter includes an electrical current oscillating circuit connected to a magnetic field-generating transmission coil. The magnetic field-generating coil preferably comprises an electromagnetic core having low hysteresis characteristics. The core is wrapped with a small coil of conductive wire. In one preferred embodiment, this power signal transmission coil acts as a primary coil of a transformer. An oscillating magnetic field is generated by passing an oscillating or alternating electrical current through the coil. The magnetic field oscillates, changing polarity at the same frequency as the oscillating current, and thereby produces a power signal that is transmitted through the electromagnet. An oscillating frequency that is lower than typical radio frequency transmissions, preferably a frequency in the range of kHz and megahertz and more, preferably in the range of about 50 kHz to about 20 MHZ and most preferably at a frequency of about 125 kHz is used according to one aspect of the invention. The passive tag similarly includes an electromagnetic coil including a small core and a small coil of conductive wire wrapped therearound. In the embodiment where the power transmitter acts as a primary transformer coil, the coil in the tag acts as a secondary transformer coil. The coil in the tag receives the electromagnetic energy when in close proximity to the power transmitting coil in the firearm. In the described embodiment, the power transmitter and the tag act together like a loosely coupled transformer. Close proximity is required for adequate power transmission to the tag. The power is appropriately received in the tag to provide a remote power source to the tag circuitry. The power signal is also preferably divided and used as a clock pulse to the circuit for producing a coded signal in the tag that is communicated back to a reader circuit that reads and decodes the coded signal to determine whether the code is that of an authorized user.
According to one advantageous embodiment, the personal identification code is preprogramed into the passive tag and the tag circuit periodically shunts (i.e., partially short-circuits) the tag coil according to a preprogrammed code in the circuit. The electromagnetic power transmission between the transmitter coil and the tag coil acts as a loose coupled transformer so that the periodic shunting of the tag coil periodically and simultaneously (i.e., at the speed of light) changes the voltage of the electrical current flowing through the power transmission coil of the transmitter. Thus, the power signal becomes a carrier signal using a signal backscatter phenomena. The change in the voltage across the primary coil caused by the shunting of the secondary coil in the identification tag corresponds to the personal identification code stored in the tag. The changes in voltage are xe2x80x9creadxe2x80x9d by a reader circuit connected to the power transmitting coil as by using a peek voltage detection circuit. The changes in voltage are converted to a digital code that is then compared to a code programmed or otherwise stored in memory in the reader circuit. If the code imposed by the tag and carried back to the reader on the power transmission signal corresponds or matches the prerecorded code in the reader memory circuit, the activation circuit effectively acts to connect the preventer to the power supply, thereby unblocking the firing mechanism.
According to another aspect of the invention, the power transmission circuit is switched xe2x80x9conxe2x80x9d to send out a power transmission signal only when a switch is actuated in the grip or stock of the firearm. The power signal transmission xe2x80x9conxe2x80x9d switch is preferably activated only when the adornment in which the passive tag is carried is in close proximity to the firearm. This preserves the energy supply in the portable power supply, using current only when the passive tag is in the proximity of the firearm.
An additional feature to preserve power, is that once the reader circuit reads and confirms the identification of an authorized user code, the preventer is actuated to enable the firing mechanism and the power transmission circuit discontinues transmitting the power signal. The interrogator circuit no longer searches for the passive tag and the authorized code programed therein. The preventer is simply maintained in the enabled firing position as long as the xe2x80x9conxe2x80x9d switch is turned on.
According to another alternative embodiment of the invention, the power transmission circuit is periodically switched xe2x80x9conxe2x80x9d to send out a power transmission signal to determine whether a passive tag is in close proximity to the grip or stock of the firearm. The power to the enabling circuitry is preferably activated when the adornment in which the passive tag is carried is in close proximity to the firearm. This preserves the energy supply in the portable power supply, using current sparingly and periodically to interrogate the surroundings and otherwise only when the passive tag is in the proximity of the firearm.
According to a firther aspect of the invention the preventer mechanism is made resistant to inertia that might cause relative movement of the internal parts of the preventer mechanism and inadvertently enable the firing mechanism due to rapid changes in movement direction of the firearm. A pair of angularly-oriented solenoids are used as the preventer to block the firing mechanism. Advantageously, a first solenoid is positioned for axial reciprocation of a blocker rod back and forth in one axial direction to block or to release the firing mechanism and a second solenoid is positioned for axial reciprocation of a second blocker rod in another axial direction, the second axial direction being at an angle to the first solenoid and at a location to prevent movement of the first blocker rod of the first solenoid. Both solenoids must be actuated away from their normal blocking positions to allow the user to fire the firearm. The angular relationship prevents inadvertent rapid change in movement direction of the firearm from moving the blocker rod of the preventer solenoid by inertia to unblock the firing mechanism. This arrangement reduces any chances of actuation caused by inertia movement of internal parts of the preventer mechanism, as by bumping, thrusting or shaking the firearm in the axial direction of the solenoid. The second solenoid is positioned in an angular relationship to the first solenoid so that inertia movement of the blocker rod of either preventer solenoid in one axial direction does not simultaneously result in inertia movement of the blocker rod of the other solenoid. An angular relationship approximating a right angle (about 90 degrees) is beneficial for this purpose. Still, much of the benefit might be obtained with different angles where available space inside of the firearm might require a different angular relationship. The likelihood of a firearm being rapidly jarred with sufficiently rapid acceleration in the precise direction of even a single solenoid (i.e., axial aligned jarring with adequate violence to move a spring-loaded blocker rod of a spring-loaded solenoid to an unblocked position) and at the same time that the user is pulling the trigger, is remote. Nevertheless, this unique dual-angled solenoid preventer arrangement advantageously reduces even further any remote chances of inadvertent mishap due to mishandling of the firearm.
According to another aspect of the present invention, the portable power supply includes a primary battery having a predetermined nominal voltage and a backup battery having the same predetermined nominal voltage. A backup circuit is connected to detect when the voltage in the primary battery falls below a predetermined minimum voltage level. Upon detection of such minimum voltage, the backup circuit couples the backup battery to the safety system. The user is signaled when the backup battery has been connected in the circuit so that battery replacement can be effectuated. The signaling mechanism may, for example, be an audible, periodic beeping signal. A timed interval between beeps might be about every one to five minutes. The signal advantageously continues as long as the backup battery is connected so that the user is continuously warned to replace the primary battery. The safety enhancement system continues to operate using the backup battery power. The user can thereby avoid situations of inability to use the firearm due to a low battery. Beneficially, the primary battery may comprise two batteries in parallel to provide maximum primary battery power and extended battery life. Also, preferably lithium batteries are used for their extended life characteristics.
According to yet another aspect of the present invention, a power conservation circuit is provided by which the power to the preventer solenoid mechanism is reduced following a specified time period after the solenoid is initially activated into a firearm usage or unblocked position. Solenoids require less current to maintain the actuated rod in the actuated position than is required for initial actuation. Thus, carrying the firearm for a prolonged period in the xe2x80x9conxe2x80x9d or ready-to-use condition with the firing mechanism unblocked does not consume power at the same rate that power is consumed in order to initially activate the solenoid. In a preferred embodiment, this power conservation circuit periodically pulses short bursts of high current with a minimum maintenance current provided between bursts. Thus, in the event that the solenoid inadvertently moves to the preventing position while it is powered with the lower current sufficient only to maintain its position, the periodic pulse of high current will return the solenoid to the unblocked position without reinitializing the entire system.
According to a further aspect of the present invention, the power transmission circuit provides an electromagnetic power signal in the form of an oscillating magnetic field at a predetermined low frequency. A system using components designed for use at 125 kHz has been found to be useful. The magnetic tag of the personal identification device imposes a backscatter signal onto the power transmission signal. The backscatter signal provides an analog version of the personal ID code. Advantageously, a frequency shift keying (FSK) coding system has been found to be useful and to reliably provide a coded return signal representing the personal ID code. The FSK coding system is very reliable and is resistant to minor fluctuations or field interruptions. In the FSK system, the tag coil is periodically shunted (partially short-circuited through a transistor across the coil terminals) and then unshunted (i.e., open circuited) at frequencies lower than the frequency of the power signal from the transmitter primary coil. For example, the secondary coil is unshunted and then shunted for a first number of cycles of the primary power signal to represent the binary number xe2x80x9c0.xe2x80x9d Then the secondary coil is unshunted and then shunted for a second number of cycles to represent the binary number xe2x80x9c1.xe2x80x9d In a specific example, eight unshunted cycles and eight shunted cycles correspond to the number zero and ten unshunted cycles and ten shunted cycles correspond to the number one in a binary code system. Thus, eight full voltage cycles of the power transmission signal followed by eight shunted cycles at a lower voltage (a 60 db drop can be reliably detected) corresponds to the number zero, and ten full voltage cycles followed by ten shunted cycles corresponds to the number one. The sequence of zeros and ones represents the personal identification code. The number of bits of memory determine the number of possible different identification codes. A binary code is therefore imposed on the power transmission signal, which power signal, according to the backscatter phenomenon, acts as a carrier signal for the return coded signal according to the code programmed in the passive tag. The use of the frequency shift key system provides reliable data transmission because it is resistant to xe2x80x9cnoisexe2x80x9d interference from other electromagnetic field sources.
According to another aspect of the invention, a small microchip forms a part of the magnetic tag. Inexpensive microchips smaller than a few square centimeters are available with many bits of programmable storage information. For example, a microchip having capability of 96 bits of information is sufficiently small to fit on or inside a finger ring. The 96 bits of information can be sequentially arranged into a large number of recordable individual codes. For example, the code and the reader may be designed so that some of the available bits signal the start position for cycling through the code in proper sequence. Each signal to shunt the tag coil may be made of four bits, one of those bits may convey parity information and three bits may convey the shunt timing, i.e., eight cycles or ten cycles. The 96 bit sequence therefore may represent about 822 different possible ID codes that could be separately preprogrammed or stored on any authorized user identification device.
According to yet another aspect of the invention, the code reader circuit in the firearm safety device is programmable. To program the system, it is turned on to transmit a power signal. A programming tag prerecorded with the secret programming code and that is preferably maintained and secured only at the manufacturing facility, is placed in the vicinity of the reader so that the reader reads the special programming code. The reader of every system is preprogrammed to recognize the special programming code and to respond to the code by putting the reader into a programming mode. Before turning the reader off, a personal ID-coded ring having the personal identification code to be authorized for use is then placed in the vicinity of the reader. In the programming mode, the reader records the code of the ring as an authorized code. When programming is completed, the ring carrying a passive tag having that authorized programmed code will activate the firearm from the prevented position to the unblocked firing position. The firearm can be reprogrammed, preferably only at the factory where the secret programing tag is secured, to authorize a different code using the same mechanism. The first code could be overwritten and made unauthorized.
According to another further aspect of the invention, the code reading circuit has a circuitry for recording a plurality of codes when in a programming mode, so that more than one personal identification code could be authorized for the same firearm. Upon the loss of any one of the authorized coded tags, the firearm could be reprogrammed to eliminate authorization of the lost code, thereby preserving the security of the firearm system.